Search results for "contrast"
showing 10 items of 1162 documents
Texture analysis in susceptibility-weighted imaging may be useful to differentiate acute from chronic multiple sclerosis lesions.
2020
To evaluate the diagnostic performance of texture analysis (TA) applied on non-contrast-enhanced susceptibility-weighted imaging (SWI) to differentiate acute (enhancing) from chronic (non-enhancing) multiple sclerosis (MS) lesions. We analyzed 175 lesions from 58 patients with relapsing-remitting MS imaged on a 3.0 T MRI scanner and applied TA on T2-w and SWI images to extract texture features. We evaluated the presence or absence of lesion enhancement on T1-w post-contrast images and performed a computational statistical analysis to assess if there was any significant correlation between the texture features and the presence of lesion activity. ROC curves and leave-one-out cross-validation…
Relevance of dynamic studies with magnetic resonance enterography in Crohn's disease.
2020
A proper quantification of the inflammatory activity in Crohn's disease (CD) lesions is needed to establish the appropriate management for each patient. The aim of this study is to evaluate the inflammatory activity of affected segments in small bowel lesions using dynamic studies of magnetic resonance enterography (MRE) in patients undergoing surgery, and their correlation with the level of inflammation and histological fibrosis of the surgical piece.A prospective, consecutive, observational, clinical study was conducted that included all the patients with small bowel CD that underwent surgery in this center between March 2011 and September 2013. Diagnosis was established according to Lenn…
MRI findings in lingual venous malformations.
2003
To describe the plain and enhanced MRI findings of lingual venous malformations and to discuss the importance of contrast medium in the differential diagnosis of high intensity lesions of the tongue on T(2) weighted images.The clinical records and MR images of eight patients affected by a lingual venous malformation were retrospectively reviewed. Patients presented with a palpable submucosal bluish-red soft mass in the tongue. MRI examinations were performed on a 0.5 T superconducting unit. Plain and enhanced SE (spin echo) T(1) weighted and FSE (fast spin echo) T(2) weighted images were acquired in axial, sagittal and coronal planes. Axial SPGR (spoiled gradient recalled echo) T(1) weighte…
Hepatic focal nodular hyperplasia: contrast-enhanced ultrasound findings with emphasis on lesion size, depth and liver echogenicity
2010
To correlate contrast-enhanced ultrasound (CEUS) findings of hepatic focal nodular hyperplasia (FNH) with lesion size, depth and liver echogenicity and to compare CEUS with baseline US. Two radiologists evaluated baseline US and CEUS examinations of 92 FNHs (mean size: 3.1 +/- 1.7 cm) in 71 patients (59 women and 12 men) to detect the "spoke-wheel" sign, central scar and feeding vessel. The FNHs were grouped and analysed by dimension, depth and liver echogenicity. At least one sign could be detected at CEUS in 27 out of 36 (75%) FNHs larger than 3 cm and in 17 out of 56 (30%) FNH measuring 3 cm or less (p 0.05) as well as between CEUS or baseline US/CD with regard to lesion size, depth or l…
Indeterminate focal liver lesions incidentally discovered at gray-scale US: role of contrast-enhanced sonography.
2011
OBJECTIVES: to assess the role of contrast-enhanced ultrasound (CEUS) in the characterization of focal liver lesions (FLLs) incidentally discovered but indeterminate at gray-scale ultrasound (US). MATERIALS AND METHODS: one hundred forty-two consecutive patients with 174 FLLs (169 benign and 5 malignant) incidentally discovered but indeterminate at gray-scale US, underwent CEUS after the administration of SonoVue. Two readers independently reviewed CEUS scans and: (1) classified each lesion as malignant or benign on a 5-point scale of confidence by means of definite diagnostic criteria; (2) provided if possible a specific diagnosis; (3) were requested if further imaging was needed for lesio…
Study of neurinomas with ultrasound contrast media: review of a case series to identify characteristic imaging patterns
2011
The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique.Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated co…
Small-Bowel Diagnosis in Patients with Familial Adenomatous Polyposis: Comparison of Push Enteroscopy, Capsule Endoscopy, Ileoscopy, and Enteroclysis
2009
BACKGROUND: Conventional upper endoscopy (EGD), EGD with side-view endoscope and ileoscopy are established procedures for endoscopic evaluation of patients with familial adenomatous polyposis (FAP). However, we still have little data on the frequency and relevance of adenomas in those parts of the small bowel which are not accessible to EGD and ileoscopy. Adenomas distal to the duodenum are found more often in FAP patients with known duodenal adenomas. The question is, whether these patients can benefit from additional endoscopic and/or radiographic examinations. METHODS: Between July 2001 and August 2006 we performed comparative small bowel studies with push enteroscopy (PE), capsule endos…
Contrast-enhanced ultrasonography: usefulness in the assessment of postoperative recurrence of Crohn's disease.
2013
Abstract Aim The aim of this study was to assess whether the contrast-enhanced ultrasonography (CEUS) can increase the value of the ultrasonography in the study of postoperative recurrence of Crohn's disease (CD). Materials and methods 60 patients with CD who had previously undergone ileocolic resection underwent prospectively both CEUS and colonoscopy within a 3-day period. The sonographic examination included evaluation of bowel wall thickness, transmural complications, colour Doppler grade and contrast-enhanced US. In addition a sonographic score was established. The capacity of CEUS to diagnose endoscopic recurrence, as well as its severity, was assessed by calculating the sensitivity, …
Spiral CT of bronchial arteries in chronic thromboembolism.
1994
OBJECTIVE: Computed tomography study of bronchial artery anatomy and evaluation of dilatation and tortuousity as indicators for pulmonary hypertension and surgical risk in patients with chronic thromboembolism were performed. MATERIALS AND METHODS: We retrospectively reviewed contrast-enhanced, thin section spiral CT scans of 39 patients undergoing pulmonary thromboendarterectomy. Findings were compared with mean pulmonary artery (PA) pressure in all, postoperative mortality in 33, and postoperative CT in 5 patients. Twenty patients without pulmonary hypertension served as controls. RESULTS: In the pulmonary hypertension group, 50 bronchial arteries were observed in 30 of 39 patients. Their…
Optical quality in eyes with aspheric intraocular lenses and in younger and older adult phakic eyes: comparative study.
2009
To compare ocular higher-order aberrations (HOAs) in eyes with aspheric intraocular lenses (IOL) and in phakic eyes.Department of Ophthalmology, Military Health Service Institute, Warsaw, Poland.Higher-order aberrations with a 5.0 mm pupil and best spectacle-corrected visual acuity (BSCVA) were analyzed in a young phakic group (age 20 to 40 years), older phakic group (age 40 to 60 years), and a pseudophakic group (age 62 to 84 years; SN60WF aspheric IOL).The mean coma was 0.13 microm+/-0.07 (SD) in the younger phakic group, 0.18+/-0.08 microm in the older phakic group, and 0.16+/-0.08 microm in the pseudophakic group; the difference between the 2 phakic groups was statistically significant …